1. Field
The present invention relates generally to wireless communication, and more specifically to control of wireless communication services.
2. Background
Allocating resources is necessary for a wireless communication system since resources available to that system can be limited for a varying number of subscribers. The purpose of controlling an admission of communication channels, i.e. flows, into the wireless communication system, is to provide a level of quality to each of the subscribers already in the system, i.e. a Quality of Service (QoS). One approach can be to limit the total amount of traffic to an appropriate level for these resources. For a system providing a variety of differentiated services, an assignment of a priority to each of the multiple communication flows can balance the conflicting objectives of high utilization of sector capacity, with the satisfaction of priority requirements. Further, due to the time varying nature of a wireless channel, some headroom in resource utilization must be left to ensure that the priority requirements are satisfied continuously throughout the entire session, even during short periods of deep fading.
Based on simulation, it has been determined that channel fading is the dominant reason for packet drops. Most of the packet drops happen when the user is in deep fading. With present systems, there is no knowledge of user mobility patterns; namely, characteristics of such long term fading are unknown. A simple way of admission control could be based on the total demand and fixed capacity obtained through averaging over all the conceived scenarios including number of flows from each QoS class, user location, mobility pattern, and so forth. After the capacity is obtained, the implemented algorithm would be purely based on the total request. Despite this simplicity, this scheme suffers from the shortcoming that the capacity number will be highly dependent on the coverage condition in the sector and it will change as new base stations are set up.